Wireless network device and user equipment, and method and system for wireless communication

ABSTRACT

The invention provides for a wireless communications terminal ( 502 ), and related system and method, for wirelessly communicating with a network ( 504, 506 ). The terminal ( 502 ) is arranged to transmit, as part of a wireless connection establishment procedure for forming a wireless connection between the terminal ( 502 ) and the network ( 504, 506 ), wireless-connection establishment signalling ( 510 ) including a small-data indicator to indicate to the network ( 504 ) that transmission of an amount of data below a threshold value is required from the terminal ( 502 ) by way of the wireless connection to the network ( 504, 506 ).

TECHNICAL FIELD

The present invention relates to Small Data transmission within awireless network environment.

BACKGROUND ART

It is established for a wireless terminal and wireless network, as partof their interoperation with each other, to perform a Radio ResourceControl (RRC) Connection Establishment procedure. This is required inorder to make the transition from RRC Idle mode to RRC Connected modeprior to any application data being transmitted between the terminal andthe network and prior to completion of any signalling procedures.

The RRC connection establishment procedure is initiated by the terminal,which is generally referred to as a user equipment (UE) in the contextof 3rd and 4th generation cellular wireless communication systemscomplying with European 3rd Generation Partnership Project (3GPP)standards, including Long Term Evolution (LTE).

In case of LTE, a non-access stratum (NAS) signalling message istransmitted as part of the RRC connection establishment procedure (inRRC Connection Setup Complete message), whereas in case of UniversalMobile Telecommunications System (UMTS) Terrestrial Radio Access Network(UTRAN), the initial NAS message is transmitted after the RRC connectionestablishment procedure.

3GPP specification TS36.331, s.6.2.2 specifies that an ‘EstablishmentCause’ is included in a RRC Connection Request message, the messageforming a first step in the RRC connection establishment procedure.

FIG. 1 is a signalling flow diagram illustrating the signalling steps ofthe RRC connection establishment procedure specified in the aforesaid3GPP specification TS36.331, s.5.3.3. Here there is illustrated awireless terminal (UE) 102 and a network 104 represented as source anddestination entities between which signals can be transmitted, thesource and destination of each signal being indicated by respectivevertical lines attached to, and associated with, the respective wirelessterminal (UE) 102 and network 104. Signals, shown as horizontal arrows110, 112, 114, are transmitted between the wireless terminal 102 and thenetwork 104. In a first step, the wireless terminal (UE) 102 transmits aRRC Connection Request message 110 to the network 104. In a second step,the network 104 transmits a RRC Connection Setup message 112 to thewireless terminal (UE) 102. In a third step, and subsequent to receiptof the signal 112, the wireless terminal (UE) 102 transmits a RRCConnection Setup Complete message 114 to the network 104.

FIG. 2 is a table including a list of possible RRC Establishment Causes,noting in particular that there are two spare values for RRC cause(Spare 1, Spare 2).

FIG. 3 is a table showing, in simplified form, a relationship betweenthe RRC cause and the (Network Access Stratum) NAS procedure asspecified in TS24.301, Annex D.1. The RRC Establishment cause isdetermined by the NAS procedure for which the connection is beingestablished. For example, for the NAS procedure “Attach”, there arethree possible RRC Establishment Causes: Mobile Originated Signalling;Delay Tolerant Access; and Emergency.

Many Machine-Type Communication (MTC) applications executed on wirelessterminals send or receive amounts of data that are much smaller thanamounts of data that are sent and/or received by other types ofapplications, for example a voice communication. Also there is a hugeincrease in ‘smart phone’ use where many applications exchange so-called‘keep-alive’ messages with the network, such messages periodicallynotifying an application, running on an equipment or server remote tothe terminal and connected to the network, that the terminal is stillconnected to the network and wants to maintain an intermittentconnection with the remote equipment or server. All this can lead toinefficient use of resources in the 3GPP system.

The 3GPP SA1 Working Group has already identified the above-mentionedtransmission/reception of small amounts of data, identified as ‘smalldata transmission’, as one of the features of MTC. 3GPP specificationTS22.368, s7.2.5, defines the MTC feature ‘Small Data Transmission’which is intended, as suggested above, for use with MTC Devices thatsend or receive small amounts of data. Observed sizes of many instancesof data exchange are of the order of 1 k octets (1,024 octets) but thisshould in no way be considered as defining or limiting the reference tosmall data within the context of the present invention. 3GPP iscurrently standardising the Machine Type Communication (MTC) and aspecific feature of MTC is that there will be many instances of a verysmall data exchange (in one or both directions), and in the order of 1IP packet for example. For this reason the 3GPP (SA1) has defined inTS22.368 a specific MTC feature called ‘Small Data Transmission’.Adoption of the present invention within, for example, 3GPP will allowfor efficient small data transmission. Reference to small data thereforecarries with it the implication such data may be treated differentlyfrom normal data. Thus, the above mentioned example in TS22.368 of 1 koctet is just one example and it should be understood that theunderstanding or definition of small data may be configurable (persubscription for example) by the network operators.

The 3GPP SA2 Working Group is currently investigating Small Datatransmission optimisation (including keep-alive messages from smartphones) as part of the MTCe-SDDTE (Small Data and Device TriggeringEnhancements) Work Item—see TR23.887, s5.1. A key issue of theinvestigation is ‘Efficient Small Data transmission’. The followingfunctional requirement for Small Data transmission was agreed inTR23.887, s.5.1.1.2:

-   -   “The system shall support transmissions of small amounts of data        efficiently with minimal network impact (e.g. signalling        overhead, network resources, delay for reallocation).”

SA2 has already agreed several possible solutions for efficient smalldata transmission in 3GPP technical report TR23.887. One of the possiblesolutions (Small Data Transfer starting from RRC IDLE, s5.1.1.3.1)includes transferring the small data as NAS signalling within RRCConnection Complete message (mentioned above) with use ofpre-established NAS security and without establishing RRC security.

-   -   For this, in section 5.1.1.3.1 of the report, the following        feature is suggested to be used: “For Small Data transmission        UE's application requests NAS to request the UE's AS to        establish an RRC connection “for a Tracking Area Update” and the        RRC Connection is established with RRC establishment cause=‘mo        signalling’ rather than cause=‘mo data’.”

The use of a “mo-signalling” (mobile originated signalling) RRC causeallows the evolved Node B (eNB) to detect that a short-lived signallingprocedure is in progress. The mo-signalling cause is employed toindicate that only signalling, and thus no data, is to be transmitted.The use of a “mo-data” cause serves to indicate to the network that datais also to be transmitted and if there is data for transmission as well,the network serves to configure the UE for measurement reporting. Smalldata would typically use a “mo-data” establishment cause and the networkthen configure the UE for measurements. Hence, it is unlikely that theMobility Management Entity (MME) will download the security context tothe eNB. Without the security context, handover cannot be performed.Thus, the eNB would not configure the UE to perform measurementreporting and radio resources would be saved. The above feature oradaptation allows the small data transmission to take place by modifyingthe behaviour of the eNB when a request for small data transmission isdetected.

However another problem exists, as stated in the TR23.887:

-   -   “Editor's Note: Interactions of Low Access Priority with        “mo-Signalling” are FFS (i.e., how can both be set as the        Establishment Cause in the RRC Connection Request).”

That is, for small data transmissions, it is here proposed that a“mo-signalling” establishment cause is used, rather than “mo-data” sothat the network does not configure the UE for measurements and sothereby save network resources.

SUMMARY OF INVENTION Technical Problem

Because of the above-proposed use of “mo-signalling” establishment causefor small data transmission, the eNB does not know that the requestedRRC connection is for Small Data transfer because the RRC cause is‘mo-signalling’. Also Small Data transmission, as suggested in the abovesolution from TR23.887, cannot be treated as low priority becausemo-signalling RRC cause is used instead of ‘Delay Tolerant Access’ RRCcause (the two cannot be used at the same time). This is a significantproblem as small data transmission originating from a MTC terminal(which would include most ‘keep-alive’ data) are in fact generally oflow priority;

Also, there would be a problem if any other Small Data-specificfunctionality must be triggered by the eNB.

Such known arrangements are therefore limited in their effectiveness inimproving efficiency of small data transmissions.

The present invention seeks to provide for wireless communicationsmethods, systems and terminal devices for small data transmission andhaving advantages over known such methods, systems and devices.

Solution to Problem

According to one aspect of the present invention there is provided awireless communications terminal arranged to wirelessly communicate witha network, the terminal being arranged to transmit, as part of awireless connection establishment procedure for forming a wirelessconnection between the terminal and the network, wireless-connectionestablishment signalling including a small-data indicator to indicate tothe network that transmission of an amount of data below a thresholdvalue is required from the terminal by way of the wireless connection tothe network.

The use of such a specific small data indicator advantageously overcomeslimitation experienced in the current art and such as those noted above.

In particular, the small-data indicator can be provided in a connectionrequest signal and can include a connection-establishment cause withinthe connection request signal.

As a further feature to enhance the adaptability of the invention, theestablishment cause can relate to the priority of the small amount ofdata to be transmitted.

Optionally, the small-data indicator can be provided as part of anInformation Element and, if so, the Information Element can include oneof an extended connection establishment cause Information Element, or anadditional-information Information Element.

Yet further, the small-data indicator can be provided within aconnection setup complete message to be sent from the wireless terminal.

In this manner, the small-data indicator can be provided as part of asmall-data indication Information Element, and the wireless connectionestablishment signalling can include a connection request signal havinga connection establishment cause of one of delay-tolerant-access ormo-signalling.

The invention can also provide for a wireless communication systemincluding a wireless communications terminal as defined above and anetwork device arranged for receiving the wireless-connectionestablishment signalling.

Further, the invention can provide for a method of operating a wirelesscommunications terminal arranged to wirelessly communicate with anetwork, including the steps of transmitting, as part of the wirelessconnection establishment procedure for forming a wireless connectionbetween the terminal and the network, wireless-connection establishmentsignalling, including a small-data indicator to indicate to the networkthat transmission of an amount of data below a threshold value isrequired from the terminal by way of the wireless connection to thenetwork.

It will be appreciated that such method can be adapted to provide forthe further function features of the terminal as discussed above.

The invention can likewise provide for a method of small-data wirelesscommunications between a wireless communications terminal and a networkdevice in a communications network, and including the steps oftransmitting from the wireless communications terminal, as part of awireless connection establishment procedure for forming a wirelessconnection between the terminal and the network, wireless-connectionestablishment signalling, including a small-data indicator to indicateto the network that transmission of an amount of data below a thresholdvalue is required from the terminal by way of the wireless connection tothe network.

Advantageous Effects of Invention

According to the present invention, it is possible to at least providefor wireless communications methods, systems and terminal devices forsmall data transmission and having advantages over known such methods,systems and devices.

BRIEF DESCRIPTION OF DRAWINGS

The invention is described further hereinafter, by way of example only,with reference to the accompanying drawings in which:

FIG. 1 is a signalling flow diagram illustrating the signalling steps ofthe RRC connection establishment procedure specified in the aforesaid3GPP specification TS36.331, s.5.3.3;

FIG. 2 is a table including a list of possible RRC Establishment Causes;

FIG. 3 is a table showing, in simplified form, a relationship betweenthe RRC cause and the (Network Access Stratum) NAS procedure asspecified in TS24.301, Annex D.1;

FIG. 4 is a table illustrating the deployment of a small data cause ofan embodiment of the invention;

FIG. 5 is a signalling diagram within a wireless network and accordingto an embodiment of the invention;

FIG. 6 is a table illustrating the deployment of mixed priority causesaccording to an embodiment of the invention;

FIG. 7 is a signalling diagram within a wireless network and accordingto the embodiment of FIG. 6;

FIG. 8 is a table illustrating the schematic structure of an informationelement (IE) bearing a small data cause according to an embodiment ofthe invention;

FIG. 9 is a signalling diagram within a wireless network and accordingto the embodiment of FIG. 8; and

FIG. 10 is a signalling diagram within a wireless network and accordingto yet a further embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

Turning first to FIG. 4, there is provided a table illustrating a newSmall Data RRC Establishment Cause according to an embodiment of theinvention. The new RRC Establishment Cause for Small Data transmissionis referred to herein by the simple identifier ‘Small Data’, asindicated by bold text in the table shown in FIG. 4. However, it will ofcourse be appreciated that any appropriate label for indicating a smallamount of data can be employed and the invention is in no way restrictedto any particular label or name for this new cause.

FIG. 5 is a signalling flow diagram illustrating the signalling steps ofa new RRC connection establishment procedure according to a firstembodiment. A wireless terminal (UE) 502 and a base station (eNB) 504 ofa network are represented as source and destination entities 502, 504between which signals can be transmitted, the source and destination ofeach signal being indicated by respective vertical lines attached to,and associated with, the respective wireless terminal (UE) 502 and basestation 504 entities. Signals, shown as horizontal arrows 510, 512, 514,are transmitted between the wireless terminal 502 and the base station504. Initially, according to a preamble for Small Data transmission, thewireless terminal 502 is attached to the network via the base station504 and in idle mode 508. Before Small Data transmission it is expectedthat the UE has already attached to the network. The UE and the MME hasalready exchanged their support/capability for Small Data transmissionand NAS security/encryption information.

In a first step, the wireless terminal (UE) 502 transmits a RRCConnection Request message 510 intended for the network 504.

By means of the message 510, the UE's application for Small Datatransmission asks the non-access stratum (NAS) to request the UE'saccess stratum (AS) to establish an RRC connection for Small Data. Thiscould be a direct request from NAS to AS or within the tracking areaupdate (TAU) message or Service Request Message or any other NASmessage. Based on this request for Small Data transmission the AS of theUE triggers RRC Connection Establishment Request with a RRCEstablishment Cause equal to ‘Small Data’. The use of the new RRCEstablishment Cause of ‘Small Data’ makes the base station (and hencethe network) aware that the requested RRC Connection is for small datatransmission.

This allows base station (eNB) to prevent measurement configurationprocedures and save radio resources. It also allows the base station totreat the Small Data transmission as a low priority (‘small data’ couldincorporate the ‘low priority’ meaning as well whereas that is notpossible by using ‘mo-signalling’ in the current art). Furthermore, itallows the base station to perform any other Small Data transmissionspecific requirement.

In a second step, the base station 504 transmits a RRC Connection Setupmessage 512 intended for the wireless terminal (UE) 502. This is theusual RRC connection Setup by the eNB.

In a third step, the wireless terminal (UE) 502 transmits a RRCConnection Setup Complete message 514 intended for the base station 504of the network. The UE includes the Small Data information as a NASprotocol data unit (PDU) IE in the RRC Connection Setup Complete message514. The NAS PDU includes the Small Data and the Evolved Packet System(EPS) bearer ID which are encrypted. The Key Set Identifier (KSI) isalso included, in unencrypted form as the MME uses it to decrypt theSmall Data and the EPS bearer ID.

The base station 504 forwards an encrypted Small Data to the MME in the51 Application Protocol (S1AP) Initial UE message 516. This message 516is initiated by the eNB 504 and is the first message received by the MME506 and originating from the UE 502 after the RRC connection isestablished. The message 516 includes both the KSI and “EPS Bearer ID”parameters from the message 514.The MME decrypts the internet protocol(IP) packet/small data, and EPS Bearer ID. Using the EPS Bearer ID, theMME retrieves the IP address and Tunnel Endpoint Identifier (TEID) ofthat bearer, forms a GPRS Tunneling Protocol for User Plane (GTP-U)packet and sends the GTP-U packet to the serving gateway (S-GW). TheS-GW sends the GTP-U packet to the Packet Data Network (PDN) Gateway(P-GW) and the P-GW forwards the GTP-U IP packet on to the SGiinterface.

The new RRC establishment cause value ‘Small Data’ provides for a clearand unambiguous indication to the base station (eNB) that the RRCconnection is needed for Small Data transmission. This allows for theeNodeB (eNB) to deploy all the right (common or specific, existing orfuture) functionality for this type of communication;

This new cause value also allows Small Data transmission to be treatedas low priority data (delay tolerant access) which is not possible ifthe ‘mo-signalling’ RRC cause is used. This is significant because 3GPPusually classifies MTC communication as low priority communication. Thisprinciple would probably apply for most of the ‘keep-alive’ data fromthe smart phones, since such ‘keep-alive’ data is typically sent insmall quantities.

The new RRC establishment cause value ‘Small Data’ prevents measurementconfiguration procedures and save radio resources. It allows for futureflexibility including easy small data transmission-related upgrades tobase stations such as the eNodeB.

The above-described new principle of Small Data transmission, includingthe new RRC establishment cause value ‘Small Data’, could also be usedwith other NAS procedures like TAU and Service Request.

FIG. 6 is a table illustrating a new High/low priority Small data RRCEstablishment Cause for small data transmission in LTE, according toanother, second, embodiment. The new RRC Establishment Cause for SmallData transmission is called either ‘High Priority Small Data’ or ‘LowPriority Small Data’, as indicated by bold text in the table shown inFIG. 6, according to whether the small data is allocated a high priorityor a low priority, respectively, the priority value (high or low) herebeing allocated for example by the wireless terminal. However it shouldbe noted that this priority could be allocated by the application thatis to transmit the small data, such that the high/low priorityconfiguration could be on a per application basis.

FIG. 7 is a signalling flow diagram illustrating the signalling steps ofa new RRC connection establishment procedure according to the secondembodiment described immediately above in relation to FIG. 6. Thesequence of events is similar to that illustrated in FIG. 5 in that,within a network environment including a UE 702, eNB 704 and MME 706,and with the UE 702 attached 708 in idle mode, RRC connection request710, RRC connection setup 712 and RRC connection setup complete 714signals are exchanged as shown between the UE 702 and the eNB 704. Thebase station 704 transmits S1AP Initial UE message 716 intended for theMME 706. A difference however is that, for Small Data that is a lowpriority (MTC and some ‘keep-alive’ messages from smart phoneapplications), the RRC connection is established with the ‘Low PrioritySmall Data’ RRC Establishment Cause by including such cause within theRRC connection request 710. On the other hand, for Small Data that isnot a low priority (this would be some ‘keep-alive’ messages from smartphone applications and any other type of Small Data transmission that isnot a low priority), the RRC connection is established with the ‘HighPriority Small Data’ RRC Establishment Cause by including such causewithin the RRC connection request 710.

According to this embodiment, it is possible to further distinguishbetween low priority small data transmission (coming mostly from MTCapplications) and higher-than-low-priority (i.e. high or normalpriority) ‘Small Data’ transmission (including for example somekeep-alive messages from smart phones and potentially some MTCapplications).

The wireless terminal 702 could be configured as NAS signalling lowpriority (see TS 24.368 s.5.3), in which case the small data would beonly of low priority. However, the wireless terminal 702 (UE) could alsobe configured to override NAS signalling priority and some applicationsin the UE may need to send high priority small data, in which case theHigh Priority Small Data RRC connection establishment cause would beneeded for the base station (eNB) 704 to understand that the data isboth high priority and small data.

It is also noted that the above-described principle of using ‘SmallData’ could be extended to functionalities and applications other thanMTC, and the generic approach described in relation to the embodimentsdescribed herein would allow this extension.

The new RRC establishment cause values ‘High Priority Small Data’ and‘Low Priority Small Data’ has the same benefits as the embodimentdescribed in relation to FIGS. 4 and 5 (‘Small Data’ cause) andadditionally has the benefit that it is clear whether the Small Data isa high priority Small Data (like some ‘keep-alive’ messages from smartphones and any other type of small data that is considered a highpriority) or low priority Small Data (like from MTC).

FIG. 8 is a table illustrating a new Small Data RRC Establishment Causefor Small Data transmission, according to a further, third, embodiment.

According to this embodiment, a new ‘Extended RRC Establishment Cause’IE or new ‘Additional Information’ IE with currently only one value‘Small Data’ is provided as part of a new RRC connection establishmentprocedure, as shown in bold in the table of FIG. 8.

FIG. 9 is a signalling flow diagram illustrating the signalling steps ofthis new RRC connection establishment procedure according to this thirdembodiment.

As seen from FIG. 9, the sequence of signalling events is similar tothat illustrated previously in that, within a network environmentincluding a UE 902, eNB 904 and MME 906, and with the UE 902 attached908 in idle mode, RRC connection request 910, RRC connection setup 912and RRC connection setup complete 914 signals are exchanged as shownbetween the UE 902 and the eNB 904. The base station 904 transmits S1APInitial UE message 916 intended for the MME 906. However, in thisparticular embodiment, an Extended RRC Establishment Cause within theRRC connection request 910 is a new IE that can be used by RRCConnection Request message (and any other RRC message) to indicate aSmall Data transmission. It could be used as an addition to the existingRRC Establishment Cause within the RRC Connection Establishment message,for example the RRC Establishment Cause=Mobile Originating Data orMobile Originating Signalling and the RRC Extended EstablishmentCause=Small Data, as seen in FIG. 9. This way the Small Datatransmission is clearly indicated to the eNB and at the same time thenew Extended RRC Establishment Cause IE is decoupled from the NAS or RRCconnection establishment procedure and it is possible to use with otherprocedures as well.

FIG. 10 is a signalling flow diagram illustrating the signalling stepsof a further new RRC connection establishment procedure according to afurther, fourth, embodiment.

According to the fourth embodiment illustrated in FIG. 10, the sequenceis that, within a network environment including a UE 1002, eNB 1004 andMME 1006, and with the UE 1002 attached in idle mode 1008, RRCconnection request 1010, RRC connection setup 1012 and RRC connectionsetup complete 1014 signals are exchanged as shown between the UE 1002and the eNB 1004. The base station 1004 transmits S1AP Initial UEmessage 1016 intended for the MME 1006. In this embodiment however, theUE 1002 transits a message 1010 asking for a RRC Connection Requestusing a RRC Establishment cause equal to ‘Delay Tolerant Access’ orequal to ‘mo-signaling’.

In the RRC Connection Setup Complete message 1014, the UE encloses thesmall data in a NAS container. The UE also includes a new ‘small dataindication’ IE in the RRC Connection Setup Complete message 1014.

The above description of embodiments includes descriptions of new RRCEstablishment Cause values: a new ‘Small Data’ RRC Establishment Causeaccording to a first embodiment; and two new ‘High Priority Small Data’and ‘Low Priority Small Data’ RRC Establishment Cause values accordingto a second embodiment. The proposed new RRC Establishment Cause valuesallow for a base station to distinguish Small Data transmission and todistinguish between High and Low Priority Small Data, so that the basestation and other nodes of the network (e.g. MME and S-GW) treat SmallData transmission appropriately.

Additionally, according to a third embodiment described above, a newExtended ‘RRC Establishment Cause’ IE or ‘Additional Information’ IE isdefined. The Extended RRC Establishment Cause IE has ‘Small Data’ causevalue to be used for Small Data transfer. It has eight more availablecause values for future use.

Additionally, according to the fourth embodiment described above, a newsmall data indication in the RRC Connection Setup Complete message isdefined. This new ‘small data indication’ is introduced to allow thebase station to be aware that the procedure is for small data, so thatthe base station can perform adequate small data-related procedures(e.g. eNB does not trigger UE measurements).

All the above embodiments are applicable to GSM/EDGE Radio AccessNetwork (GERAN) and UTRAN wireless access technologies. The onlydifferences to the above described solutions for LTE are the following:

-   (a) The eNB node in LTE is equivalent to Base Station in GERAN and    to Radio Network Controller (RNC) in UTRAN;-   (b) The MME node in LTE is the equivalent to Serving GPRS Support    Node (SGSN) in GERAN and UTRAN;-   (c) Whereas in LTE the Small Data is transferred from the UE to eNB    within the RRC Connection Establishment procedure (in RRC Connection    Setup Complete message), in GERAN and UTRAN the Small Data is    transferred from UE to Base Station in GERAN or to RNC in UTRAN    immediately after the end of the RRC connection Establishment    procedure.-   (d) The RRC Establishment Cause in GERAN is known as RR    Establishment Cause and has a different format and set of cause    values. However the proposed new ‘Small Data’ cause value is equally    applicable for RR Establishment Cause in GERAN as well.

This application is based upon and claims the benefit of priority fromUnited Kingdom Patent Application No. 1305796.3, filed on Mar. 28, 2013,the disclosure of which is incorporated herein in its entirety byreference.

INDUSTRIAL APPLICABILITY

The present invention can be applied to small data transmission within awireless network environment.

REFERENCE SIGNS LIST

-   102, 502, 702, 902, 1002 UE-   104 NETWORK-   110, 510 RRC CONNECTION REQUEST MESSAGE-   112, 512 RRC CONNECTION SETUP MESSAGE-   114, 514 RRC CONNECTION SETUP COMPLETE MESSAGE-   504, 704, 904, 1004 eNB-   506, 706, 906, 1006 MME-   516, 716, 916, 1016 S 1AP INITIAL UE MESSAGE-   710, 910, 1010 RRC CONNECTION REQUEST SIGNAL-   712, 912, 1012 RRC CONNECTION SETUP SIGNAL-   714, 914, 1014 RRC CONNECTION SETUP COMPLETE SIGNAL

1. A user equipment (UE) arranged to wirelessly communicate with anetwork, the UE being configured to: transmit a Radio Resource Control(RRC) Connection Request message as part of a wireless connectionestablishment procedure for forming a wireless connection between the UEand the network, wherein said RRC Connection Request message includes anRRC establishment cause, wherein the RRC establishment cause isconfigurable to include any of a plurality of different cause indicatorsincluding: a mobile terminating access (mt-Access) indicator, a mobileoriginating data (mo-data) indicator, and at least one further indicatorof mobile originating data that is used for the UE when operating in asmall data transmission mode.
 2. The user equipment according to claim1, wherein the at least one further indicator of mobile originating datais associated with the UE when operating in a machine type communicationmode.
 3. The user equipment according to claim 1, wherein the pluralityof different cause indicators includes a mobile originating signalling(mo-signalling) indicator.
 4. The user equipment according to claim 1,wherein the plurality of different cause indicators includes a delaytolerant access indicator.
 5. A method of operating a user equipment(UE) arranged to wirelessly communicate with a network, comprising:transmitting a Radio Resource Control (RRC) Connection Request messageas part of a wireless connection establishment procedure for forming awireless connection between the UE and the network, said RRC ConnectionRequest message including an RRC establishment cause, wherein the RRCestablishment cause is configurable to include any of a plurality ofdifferent cause indicators, including: a mobile terminating access(mt-Access) indicator, a mobile originating data (mo-data) indicator,and at least one further indicator of mobile originating data that isused for the UE when operating in a small data transmission mode.
 6. Themethod according to claim 5, wherein the at least one further indicatorof mobile originating data is associated with the UE when operating in amachine type communication mode.
 7. The method according to claim 5,wherein the plurality of different cause indicators includes a mobileoriginating signalling (mo-signalling) indicator.
 8. The methodaccording to claim 5, wherein the plurality of different causeindicators includes a delay tolerant access indicator.
 9. A networkdevice arranged to wirelessly communicate with a user equipment (UE),the network device being arranged to receive a Radio Resource Control(RRC) Connection Request message as part of a wireless connectionestablishment procedure for forming a wireless connection between the UEand the network, said RRC Connection Request message including an RRCestablishment cause, wherein the RRC establishment cause is configurableto include any of a plurality of different cause indicators including: amobile terminating access (mt-Access) indicator, a mobile originatingdata (mo-data) indicator, and at least one further indicator of mobileoriginating data that is used for the UE when operating in a small datatransmission mode.
 10. The network device according to claim 9, whereinthe at least one further indicator of mobile originating data isassociated with the UE when operating in a machine type communicationmode.
 11. The network device according to claim 9, wherein the pluralityof different cause indicators includes a mobile originating signalling(mo-signalling) indicator.
 12. The network device according to claim 9,wherein the plurality of different cause indicators includes a delaytolerant access indicator.
 13. A wireless communication system,comprising: the UE according to claim 1; and a network device arrangedto wirelessly communicate with the user equipment, the network devicebeing arranged to receive the RRC Connection Request message.
 14. Thewireless communication system according to claim 13, wherein the atleast one further indicator of mobile originating data is associatedwith the UE when operating in a machine type communication mode.
 15. Thewireless communication system according to claim 13, wherein theplurality of different cause indicators includes a mobile originatingsignalling (mo-signalling) indicator.
 16. The wireless communicationsystem according to claim 13, wherein the plurality of different causeindicators includes a delay tolerant access indicator.